Show the sync indicator only when there's a diff to be applied or uploaded

lib/events/sync_status_update_event.dart

@@ -17,7 +17,9 @@ class SyncStatusUpdate extends Event {
 }
 
 enum SyncStatus {
-  not_started,
+  applying_local_diff,
+  applying_remote_diff,
+  preparing_for_upload,
   in_progress,
   paused,
   completed,

lib/services/sync_service.dart

@@ -75,12 +75,13 @@ class SyncService {
       return _existingSync;
     }
     _isSyncInProgress = true;
-    Bus.instance.fire(SyncStatusUpdate(SyncStatus.not_started));
     _existingSync = Future<void>(() async {
       _logger.info("Syncing...");
       try {
         await _doSync();
-        Bus.instance.fire(SyncStatusUpdate(SyncStatus.completed));
+        if (_lastSyncStatusEvent != null) {
+          Bus.instance.fire(SyncStatusUpdate(SyncStatus.completed));
+        }
       } on WiFiUnavailableError {
         _logger.warning("Not uploading over mobile data");
         Bus.instance.fire(
@@ -151,6 +152,7 @@ class SyncService {
         getMonthAndYear(DateTime.fromMicrosecondsSinceEpoch(toTime)));
     final files = await getDeviceFiles(fromTime, toTime);
     if (files.isNotEmpty) {
+      Bus.instance.fire(SyncStatusUpdate(SyncStatus.applying_local_diff));
       _logger.info("Fetched " + files.length.toString() + " files.");
       final updatedFiles =
           files.where((file) => existingLocalFileIDs.contains(file.localID));
@@ -178,6 +180,9 @@ class SyncService {
       return Future.error("Account not configured yet");
     }
     final updatedCollections = await _collectionsService.sync();
+    if (updatedCollections.isNotEmpty) {
+      Bus.instance.fire(SyncStatusUpdate(SyncStatus.applying_remote_diff));
+    }
     for (final collection in updatedCollections) {
       await _fetchEncryptedFilesDiff(collection.id);
     }
@@ -217,6 +222,10 @@ class SyncService {
     int uploadCounter = 0;
     final totalUploads = filesToBeUploaded.length + updatedFileIDs.length;
 
+    if (totalUploads > 0) {
+      Bus.instance.fire(SyncStatusUpdate(SyncStatus.preparing_for_upload));
+    }
+
     for (final uploadedFileID in updatedFileIDs) {
       if (_syncStopRequested) {
         _syncStopRequested = false;

lib/ui/sync_indicator.dart

@@ -16,7 +16,6 @@ class SyncIndicator extends StatefulWidget {
 class _SyncIndicatorState extends State<SyncIndicator> {
   SyncStatusUpdate _event;
   double _containerHeight = 48;
-  int _latestCompletedCount = 0;
   StreamSubscription<SyncStatusUpdate> _subscription;
 
   @override
@@ -24,10 +23,6 @@ class _SyncIndicatorState extends State<SyncIndicator> {
     _subscription = Bus.instance.on<SyncStatusUpdate>().listen((event) {
       setState(() {
         _event = event;
-        if (_event.status == SyncStatus.in_progress &&
-            _event.completed > _latestCompletedCount) {
-          _latestCompletedCount = _event.completed;
-        }
       });
     });
     _event = SyncService.instance.getLastSyncStatusEvent();
@@ -70,7 +65,7 @@ class _SyncIndicatorState extends State<SyncIndicator> {
         duration: Duration(milliseconds: 300),
         height: _containerHeight,
         width: double.infinity,
-        margin: EdgeInsets.all(8),
+        padding: EdgeInsets.all(8),
         alignment: Alignment.center,
         child: SingleChildScrollView(
           physics: NeverScrollableScrollPhysics(),
@@ -83,12 +78,12 @@ class _SyncIndicatorState extends State<SyncIndicator> {
                 crossAxisAlignment: CrossAxisAlignment.center,
                 children: [
                   Container(
-                    width: 24,
-                    height: 24,
+                    width: 20,
+                    height: 20,
                     child: icon,
                   ),
                   Padding(
-                    padding: const EdgeInsets.fromLTRB(8, 4, 0, 0),
+                    padding: const EdgeInsets.fromLTRB(12, 4, 0, 0),
                     child: Text(_getRefreshingText()),
                   ),
                 ],
@@ -104,27 +99,31 @@ class _SyncIndicatorState extends State<SyncIndicator> {
   }
 
   String _getRefreshingText() {
-    if (_event == null || _event.status == SyncStatus.not_started) {
+    if (_event == null ||
+        _event.status == SyncStatus.applying_local_diff ||
+        _event.status == SyncStatus.applying_remote_diff) {
       return "Syncing...";
-    } else {
-      var s;
-      if (_event.status == SyncStatus.error) {
-        s = "Upload failed.";
-      } else if (_event.status == SyncStatus.completed) {
-        if (_event.wasStopped) {
-          s = "Sync stopped.";
-        } else {
-          s = "All memories preserved.";
-        }
-      } else if (_event.status == SyncStatus.paused) {
-        s = _event.reason;
-      } else {
-        s = _latestCompletedCount.toString() +
-            "/" +
-            _event.total.toString() +
-            " memories preserved";
-      }
-      return s;
     }
+    if (_event.status == SyncStatus.preparing_for_upload) {
+      return "Preparing backup...";
+    }
+    if (_event.status == SyncStatus.in_progress) {
+      return _event.completed.toString() +
+          "/" +
+          _event.total.toString() +
+          " memories preserved.";
+    }
+    if (_event.status == SyncStatus.paused) {
+      return _event.reason;
+    }
+    if (_event.status == SyncStatus.completed) {
+      if (_event.wasStopped) {
+        return "Sync stopped.";
+      } else {
+        return "All memories preserved.";
+      }
+    }
+    // _event.status == SyncStatus.error)
+    return "Upload failed.";
   }
 }